Out of Alaska: morphological diversity within the genus <Emphasis Type="Italic">Eurytemora</Emphasis> from its ancestral Alaskan range (Crustacea,Copepoda) |
| |
Authors: | Stanley I Dodson Daniel A Skelly Carol Eunmi Lee |
| |
Institution: | (1) Department of Zoology, University of Wisconsin, 430 Lincoln Drive, Madison, WI 53706-1381, USA;(2) Center of Rapid Evolution (CORE), University of Wisconsin, 430 Lincoln Drive, Birge Hall, Madison, WI 53706, USA;(3) Present address: Department of Genome Sciences, University of Washington, Seattle, WA 98195-5065, USA; |
| |
Abstract: | The copepod genus Eurytemora occupies a wide range of habitat types throughout the Northern Hemisphere, with among the broadest salinity ranges of any
known copepod. The epicenter of diversity for this genus lies along coastal Alaska, where several species are endemic. Systematic
analysis has been difficult, however, because of a tendency toward morphological stasis in this genus, despite large genetic
divergences among populations and species. The goals of this study were to (1) analyze patterns of morphological variation
and divergence within this genus, focusing on Eurytemora species that occur in North America, and (2) determine patterns of geographic and salinity distribution of Eurytemora species within the ancestral range in Alaska. We applied a comparative multivariate morphological analysis using 16–26 characters
from 125 specimens from 20 newly collected sites in Alaska and 15 existing samples predominantly from North America. Results
from principal component and hierarchical cluster analyses identified seven distinct morphological species of Eurytemora in North America (E. affinis, E. americana, E. canadensis, E. composita, E. herdmani, E. pacifica, and E. raboti), and identified diagnostic characters that distinguish the species (forming the basis for a new identification key). Several
previously named species were regarded as synonyms. The sites we sampled in Alaska were remarkable in the high levels of sympatry
of Eurytemora species, to a degree not seen outside of Alaska. Future studies of Eurytemora should shed light on patterns of habitat invasions and physiological evolution within the genus, and yield insights into
mechanisms leading to its remarkably broad geographic and habitat range. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|